The result of a five-year investigation has claimed that diet changes are responsible for certain speech sounds.
Human speech now consists of over 2,000 sounds, from the ever-present "m" and "a" to the clicks of some African languages. However, some sounds are clearly more common than others.
According to NewScientist, the investigation has led to the theory that changes in food intake is what led to the introductions of new sounds now found in half of the world's languages.
Linguist Charles Hockett claimed 30 years that speech sounds called labiodentals such as "f" and "v" were more common in the languages of societies that ate softer foods.
A team of researchers led by Damian Blasi at the University of Zurich, Switzerland sought to find out why this was and are now claiming that the upper and lower incisors of ancient human adults were aligned, making it harder to pronounce "f" and "v" sounds as the lower lip needs to touch the upper teeth in order for such labiodentals to be produced.
It is said that our jaws changed to an overbite structure - with the top row of incisors covering the bottom row - making it much easier to pronounce the sounds. And this was all due to the development of agriculture in the Neolithic period, when food became easier to deal with as it took way less effort from the jawbone to chew softer, farmed foods.
“The set of speech sounds we use has not necessarily remained stable since the emergence of our species, but rather the immense diversity of speech sounds that we find today is the product of a complex interplay of factors involving biological change and cultural evolution,” Steven Moran, a linguist and a member of the aforementioned team.
This new research debunks the view that all human sounds were present from the very start of our existence as a species.
“For the first time, we can look at patterns in global data and spot new relationships between the way we speak and the way we live,” says the University of Bristol's Sean Roberts. “It’s an exciting time to be a linguist.”